1.6 KiB
1.6 KiB
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Global Scope and Functions |
Global Scope and Functions
The scope of a variable is its visibility; where in the code is the function available? Here is a list of the different scopes a variable can have.
- Global scope: The variable is available throughout the code
- Local scope: Available in only a certain area (like only within function)
- Block scope: Available within an even more certain area (like an if-statement)
Your task is to understand how adding var
(and not adding) before a variable name, can change the variable's scope.
When you add var
before the variable name, its scope is determined by where it is placed. Like so:
var num1 = 18; // Global scope
function fun() {
var num2 = 20; // Local (Function) Scope
if (true) {
var num3 = 22; // Block Scope (within an if-statement)
}
}
When you don't, this is the result:
num1 = 18; // Global scope
function fun() {
num2 = 20; // Global Scope
if (true) {
num3 = 22; // Global Scope
}
}
Alright, here is the basic code solution.
// Declare your variable here
var myGlobal = 10;
function fun1() {
oopsGlobal = 5;
}
// Only change code above this line
function fun2() {
var output = "";
if (typeof myGlobal != "undefined") {
output += "myGlobal: " + myGlobal;
}
if (typeof oopsGlobal != "undefined") {
output += " oopsGlobal: " + oopsGlobal;
}
console.log(output);
}